The terms "stain" and "staining" as used herein with reference to synthetic fibers mean discoloration of the fibers caused by a reaction with a chemical substance. Acid dyes are representative of a staining material for nylon fibers.
The terms "fixed item" or "fixed items" as used herein refers to articles made from synthetic polymer fibers which articles are too large, bulky or have some other characteristic which makes the articles impractical to remove for conventional laundering or dry cleaning. Throughout this document, the term "carpet" may be used to provide clarity. It is intended that the use of the term "carpet" embraces other fixed items as well.
The terms "fiber" or "fibers" as used herein include fibers of extreme or indefinite length (i.e. filaments) and fibers of short length (i.e. staple). The terms "yarn" or "yarns" as used herein mean a continuous strand of fibers.
Carpets containing synthetic polymer fibers are a popular floor covering for both residential and commercial applications. Synthetic polymer fibers are also popular for making upholstery and wall coverings. Such fibers make carpets, upholstery, etc., that are relatively inexpensive and have a combination of desirable qualities, such as durability, comfort, safety, warmth, and quietness.
Various types of synthetic polymer fibers are used in making carpets, upholstery and the like. Two popular synthetic polymer fibers utilized in carpets are polyamide fibers, such as nylon 6, and nylon 6/6, and polyester fibers.
The fibers contained in the carpets and other fixed items are severely and permanently stained when contacted, such as by inadvertent spilling, with certain artificial and natural colorants present in household items, such as tea, coffee beverages made from coffee beans, and soft drink beverages. Carpets, upholstery and other similarly large or bulky items cannot be removed for cleaning because of the expense involved in doing so or the potential damage to the item. For example, a wall-to-wall carpet is nearly impossible to remove for cleaning because furniture must be removed from the room, etc. Even if it were feasible to remove the carpet, laundering facilities are not equipped with machines large enough to handle the carpet. Even if conventional laundering was possible, it is likely that the fixed item would lose its appearance in the conventional process. As a result, unsightly stains cause carpets and other fixed items to be replaced even though the item has not been worn out.
In an attempt to prevent undesirable staining of fibers and, particularly, fibers contained in carpets, it has been proposed that the fibers be treated with a material which makes the fiber resistant to staining. Examples of such materials are condensation products made from aromatic sulfonic acids, and formaldehyde. Although such materials have been somewhat successful in imparting stain resistance, certain problems remain. For instance, many of the materials reduce staining of fibers, but do not totally eliminate it. In addition, traffic on carpet wears off the materials, which leaves the resulting fibers of the carpet with little or no protection against staining.
Colored food beverages, such as colored soft drink beverages, tea beverages, and coffee beverages made from coffee beans, present a serious staining problem to synthetic fibers. Coffee stains are particularly unsightly because of their dark brown color. Also, coffee stains are notoriously difficult to remove from many synthetic fibers. Other common household and commercial products also severely stain synthetic materials.
Various fluorochemicals have been applied to carpet fibers in order to reduce their water and oil wettability. The fluorochemical reduces the tendency of soils to adhere to the fibers, thereby making the removal of soils from the carpet fibers easier than if the fluorochemicals were omitted, but offers little protection to the carpet fibers from spills containing acid dye colorants unless the colorants are immediately removed from the fibers. In addition, traffic on the carpet wears off the fluorochemicals.
A number of cleaning solutions have been proposed in the past for removing stains from fibers. For instance, volatile solvent dry-cleaning fluids have been proposed, but such fluids are less than satisfactory in removing water-soluble stains. In addition, aqueous compositions containing synthetic detergents have been proposed for removing stains from fibers, but such compositions have not been found to be particularly effective and tend to leave dirt collecting residues. As a result thereof, the carpet fibers become tacky due to a film of detergent. The film attracts and retains soils, which results in a cleaned carpet that will soil more easily after a cleaning than prior thereto.
One of the problems with cleaning solutions is that while they may, at times, loosen and/or disperse the soil, they fail to pick up or retain the soil, which results in the soil being redeposited on the fibers. Furthermore, they are not very effective against difficult stains, such as acid and coffee stains. Still further, since acid and coffee stains are believed to bond chemically with the fiber, aqueous detergent compositions are not particularly effective and many times it is difficult to remove all of the detergent from the fiber surface, even when rinsed with large amounts of water or steam.
Another problem with cleaning agents is that they may damage the fiber or its properties, e.g., color, strength, etc. Many available cleaning agents are either too harsh or, if sufficiently mild, ineffective against stains.
The present invention provides a cleaning composition suitable for removing stains from synthetic polymer fibers which overcomes, or at least mitigates, many of the above-described problems.